Packaged acoustic wave devices with multi-layer piezoelectric substrate

ABSTRACT

Aspects of this disclosure relate to a packaged acoustic wave component with two acoustic wave devices interconnected by a thermally conductive frame, at least one of the acoustic wave devices including a multi-layer piezoelectric substrate. The multi-layer piezoelectric substrate includes a support layer and a piezoelectric layer disposed over the support layer. An interdigital transducer (IDT) electrode is disposed over the piezoelectric layer. The support layer has a high thermal conductivity, allowing heat generated by a first acoustic wave device with the multi-layer piezoelectric substrate to be transferred to a second acoustic wave device on which it is stacked to dissipate heat from the first acoustic wave device by way of the thermally conductive frame.

INCORPORATION BY REFERENCE TO ANY PRIORITY APPLICATIONS

Any and all applications for which a foreign or domestic priority claimis identified in the Application Data Sheet as filed with the presentapplication are hereby incorporated by reference under 37 CFR 1.57.

BACKGROUND Technical Field

Embodiments of this disclosure relate to acoustic wave devices.

Description of Related Technology

Acoustic wave filters can be implemented in radio frequency electronicsystems. For instance, filters in a radio frequency front end of amobile phone can include acoustic wave filters. An acoustic wave filtercan filter a radio frequency signal. An acoustic wave filter can be aband pass filter. A plurality of acoustic wave filters can be arrangedas a multiplexer. For example, two acoustic wave filters can be arrangedas a duplexer.

An acoustic wave filter can include a plurality of resonators arrangedto filter a radio frequency signal. Example acoustic wave filtersinclude surface acoustic wave (SAW) filters and bulk acoustic wave (BAW)filters. A surface acoustic wave resonator can include an interdigitaltransductor electrode on a piezoelectric substrate. The surface acousticwave resonator can generate a surface acoustic wave on a surface of thepiezoelectric layer on which the interdigital transductor electrode isdisposed.

Reduction in the size of an acoustic wave filter can be achieved byusing stacked SAW packages (e.g., temperature compensated surfaceacoustic wave (TCSAW) filters) having stacked wafers. However, suchstructures have power durability limitations due to lower thermaldissipation on the upper wafer.

SUMMARY

Accordingly, there is a need for a surface acoustic wave (e.g., SAW orTCSAW) package with improved thermal dissipation performance, resultingin higher power durability performance.

In accordance with one aspect of the disclosure, a packaged acousticwave component is provided. The packaged acoustic wave componentcomprises a first acoustic wave device including a first multi-layerpiezoelectric substrate and a first interdigital transducer electrode.The first multi-layer piezoelectric substrate includes a firstpiezoelectric layer and support layer, the support layer having a higherthermal conductivity than the first piezoelectric layer. The packagedacoustic wave component also comprises a second acoustic wave deviceincluding a second piezoelectric layer and second interdigitaltransducer electrode. The first acoustic wave device is stacked with thesecond acoustic wave device so that the first and second interdigitaltransducer electrodes face and are spaced apart from each other. Thepackaged acoustic wave component also comprises a thermally conductiveframe interposed between the first and second acoustic wave devices. Thefirst multi-layer piezoelectric substrate is configured to direct heatgenerated by the first acoustic wave device to the second acoustic wavedevice by way of the thermally conductive frame to dissipate heat fromthe first acoustic wave device.

In accordance with another aspect of the disclosure, a packaged acousticwave component is provided. The packaged acoustic wave componentcomprises a first acoustic wave device including a first multi-layerpiezoelectric substrate having a first piezoelectric layer disposed overa first support layer, and having a first interdigital transducerelectrode. The packaged acoustic wave component also comprises a secondacoustic wave device including a second piezoelectric layer and secondinterdigital transducer electrode. The first acoustic wave device isstacked with the second acoustic wave device so that the first andsecond interdigital transducer electrodes face and are spaced apart fromeach other. The packaged acoustic wave component also comprises athermally conductive frame interposed between the first and secondacoustic wave devices and in contact with the first support layer. Thefirst multi-layer piezoelectric substrate is configured to direct heatgenerated by the first acoustic wave device to the second acoustic wavedevice by way of the thermally conductive frame to dissipate heat fromthe first acoustic wave device.

In accordance with another aspect of the disclosure, a radio frequencymodule is provided. The radio frequency module comprises a packagesubstrate and a package acoustic wave component. The package acousticwave component includes a first acoustic wave device including a firstmulti-layer piezoelectric substrate with a first piezoelectric layerdisposed over a first support layer and a first interdigital transducerelectrode. The package acoustic wave component also comprises a secondacoustic wave device including a second piezoelectric layer and secondinterdigital transducer electrode. The first acoustic wave device isstacked with the second acoustic wave device so that the first andsecond interdigital transducer electrodes face and are spaced apart fromeach other. A thermally conductive frame is interposed between the firstand second acoustic wave devices, the first multi-layer piezoelectricsubstrate being configured to direct heat generated by the firstacoustic wave device to the second acoustic wave device by way of thethermally conductive frame to dissipate heat from the first acousticwave device. The radio frequency module further comprises additionalcircuitry, the packaged acoustic wave component and additional circuitrydisposed on the package substrate.

In accordance with another aspect of the disclosure, a wirelesscommunication device is provided. The wireless communication devicecomprises an antenna and a front end module including one or morepackaged acoustic wave components configured to filter a radio frequencysignal associated with the antenna. Each surface acoustic wave componentincludes a first acoustic wave device including a first multi-layerpiezoelectric substrate with a first piezoelectric layer disposed over afirst support layer and a first interdigital transducer electrode. Eachsurface acoustic wave component also includes a second acoustic wavedevice with a second piezoelectric layer and second interdigitaltransducer electrode. The first acoustic wave device is stacked with thesecond acoustic wave device so that the first and second interdigitaltransducer electrodes face and are spaced apart from each other. Athermally conductive frame is interposed between the first and secondacoustic wave devices, the first multi-layer piezoelectric substratebeing configured to direct heat generated by the first acoustic wavedevice to the second acoustic wave device by way of the thermallyconductive frame to dissipate heat from the first acoustic wave device.

In accordance with another aspect of the disclosure, a method ofmanufacturing a packaged acoustic wave component is provided. The methodcomprises providing a first acoustic wave device including a multi-layerpiezoelectric substrate structure with a first piezoelectric layerdisposed over a first support layer and an interdigital transducerelectrode. The method also comprises stacking the first acoustic wavedevice relative to a second acoustic wave device such that a thermallyconductive frame extends between the first acoustic wave device and thesecond acoustic wave device, the thermally conductive frame providing athermal path for heat dissipation from the first acoustic wave device tothe second acoustic wave device.

In accordance with another aspect of the disclosure, a method ofdissipating heat for packaged acoustic wave component is provided. Themethod comprises generating an acoustic wave using a first acoustic wavedevice that includes a multi-layer piezoelectric substrate structurewith a first piezoelectric layer disposed over a first support layer anda first interdigital transducer electrode. The method also comprisesdissipating heat associated with the first acoustic wave device using athermal path that includes a thermally conductive frame extending fromthe first acoustic wave device to a second acoustic wave device, thefirst acoustic wave device being stacked relative to the second acousticwave device, and the second acoustic wave device having a secondinterdigital transducer electrode that faces and is spaced apart fromthe first interdigital transducer electrode.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of this disclosure will now be described, by way ofnon-limiting example, with reference to the accompanying drawings.

FIG. 1 illustrates a schematic cross-sectional side view of aconventional stacked surface acoustic wave device structure.

FIG. 2 illustrates a schematic side view of heat flow in the stackedsurface acoustic wave device structure of FIG. 1.

FIG. 3 illustrates a schematic cross-sectional side view of a stackedMulti-layer piezoelectric substrate (MPS) structure.

FIG. 4 illustrates a schematic side view of heat flow in the stacked MPSstructure of FIG. 3.

FIG. 5 illustrates a schematic cross-sectional side view of a stackedMulti-layer piezoelectric substrate (MPS) structure.

FIG. 6 illustrates a schematic side view of heat flow in the stacked MPSstructure of FIG. 5.

FIG. 7A illustrates a partial perspective view of a stacked MPSstructure and thermal performance for same.

FIG. 7B illustrates a cross-sectional side view of the stacked MPSstructure of FIG. 7A and thermal performance for same.

FIG. 8A is a schematic diagram of a transmit filter that includes asurface acoustic wave resonator according to an embodiment.

FIG. 8B is a schematic diagram of a receive filter that includes asurface acoustic wave resonator according to an embodiment.

FIG. 9 is a schematic diagram of a radio frequency module that includesa surface acoustic wave resonator according to an embodiment.

FIG. 10 is a schematic diagram of a radio frequency module that includesfilters with surface acoustic wave resonators according to anembodiment.

FIG. 11 is a schematic block diagram of a module that includes anantenna switch and duplexers that include a surface acoustic waveresonator according to an embodiment.

FIG. 12A is a schematic block diagram of a module that includes a poweramplifier, a radio frequency switch, and duplexers that include asurface acoustic wave resonator according to an embodiment.

FIG. 12B is a schematic block diagram of a module that includes filters,a radio frequency switch, and a low noise amplifier according to anembodiment.

FIG. 13A is a schematic block diagram of a wireless communication devicethat includes a filter with a surface acoustic wave resonator inaccordance with one or more embodiments.

FIG. 13B is a schematic block diagram of another wireless communicationdevice that includes a filter with a surface acoustic wave resonator inaccordance with one or more embodiments.

DETAILED DESCRIPTION

The following description of certain embodiments presents variousdescriptions of specific embodiments. However, the innovations describedherein can be embodied in a multitude of different ways, for example, asdefined and covered by the claims. In this description, reference ismade to the drawings where like reference numerals can indicateidentical or functionally similar elements. It will be understood thatelements illustrated in the figures are not necessarily drawn to scale.Moreover, it will be understood that certain embodiments can includemore elements than illustrated in a drawing and/or a subset of theelements illustrated in a drawing. Further, some embodiments canincorporate any suitable combination of features from two or moredrawings.

Acoustic wave filters can filter radio frequency (RF) signals in avariety of applications, such as in an RF front end of a mobile phone.An acoustic wave filter can be implemented with surface acoustic wave(SAW) devices. SAW devices include SAW resonators, SAW delay lines, andmulti-mode SAW (MMS) filters (e.g., double mode SAW (DMS) filters). Anyfeatures of the SAW resonators and/or devices discussed herein can beimplemented in any suitable SAW device.

In general, high quality factor (Q), large effective electromechanicalcoupling coefficient (k²), high frequency ability, and spurious freeresponse can be significant aspects for acoustic wave elements to enablelow-loss filters, delay lines, stable oscillators, and sensitivesensors.

Multi-layer piezoelectric substrate (MPS) SAW resonators can thermallyinsulate an interdigital transducer electrode and a piezoelectric layer.By reducing dissipative thermal impedance of the SAW device, theruggedness and power handling can be improved.

Some MPS SAW resonators have achieved high Q by confining energy andgood thermal dissipation using a silicon (Si) support layer. However,such approaches have encountered technical challenges related toundesirable higher frequency spurious responses.

Some other MPS SAW resonators have achieved high Q by confining energyand have also reduced higher frequency spurious responses. However, suchapproaches have encountered relatively low thermal heat dissipation.

Aspects of the present disclosure relate to SAW resonators that includea support substrate or layer (e.g., a single crystal supportingsubstrate), a functional layer (e.g., a dielectric layer) over thesupport substrate or layer, a piezoelectric layer (e.g., a lithiumniobate (LN) layer or a lithium tantalate (LT) layer) over thefunctional layer, and an interdigital transducer (IDT) electrode overthe piezoelectric layer. Such SAW resonators can also include atemperature compensation layer (e.g., silicon dioxide (SiO2) layer) overthe IDT electrode in certain embodiments. The SAW resonators can alsoinclude an adhesion layer disposed between the support substrate and thefunctional layer and/or an adhesion layer between the functional layerand the piezoelectric layer, in certain applications.

SAW resonators with the functional layer and the support layer orsubstrate can beneficially provide a relatively high effectiveelectromechanical coupling coefficient (k²), a relatively high qualityfactor (Q), a relatively high power durability and thermal dissipation,and reduced high frequency spurious responses. The high couplingcoefficient (k²) can be beneficial for relatively wide bandwidthfilters. The high quality factor (Q) can beneficially lead to arelatively low insertion loss. The reduced high frequency spurious maymake the SAW resonators compatible with multiplexing with higherfrequency bands.

In an embodiment, an MPS SAW resonator includes a piezoelectric layerover a functional layer over a silicon support substrate or layer. Thesilicon support substrate can reduce thermal impedance of the MPS SAWresonator. The functional layer can be a single crystal layer arrangedto confine acoustic energy and lower a higher frequency spuriousresponse. The piezoelectric layer, the functional layer, and the siliconsupport substrate can all be single crystal layers.

Embodiments of MPS SAW resonators will now be discussed. Any suitableprinciples and advantages of these MPS SAW resonators can be implementedtogether with each other in an MPS SAW resonator and/or in an acousticwave filter. MPS SAW resonators disclosed herein can have lower lossthan certain bulk acoustic wave devices.

FIGS. 1-2 illustrate a conventional surface acoustic wave (SAW) packageor stacked surface acoustic wave device structure 50 with a firstsurface acoustic wave (SAW) resonator or device 10 and a second SAWresonator or device 20, the first SAW device 10 supported by a frame 30on the second SAW device 20. The first and second SAW resonators ordevices 10, 20 each have a piezoelectric substrate 12, 22 and aninterdigital transducer (IDT) electrode 14, 24 disposed on thepiezoelectric substrate 12. The piezoelectric substrate 12, 22 is madeof lithium tantalite (LT) or lithium niobite (LN). Vias 18 extendbetween metal layers 16, 26 attached to the IDT electrodes 14, 24 of thefirst and second SAW resonators or devices 10, 20. The second SAWresonator 20 has vias 28 that extend through the piezoelectric substrate22 from the IDT electrode 24 to electrodes 29 on an opposite side of thepiezoelectric substrate 22 from the IDT electrode 24.

As shown in FIG. 2, heat generated by the IDT electrode 14 of the firstSAW resonator or device 10, shown by arrows H1, is trapped in thepiezoelectric substrate 12 (e.g., due to LN and LT having a poor thermalconductivity), causing the temperature of the piezoelectric substrate 12and first SAW resonator 10 to increase. Testing of the SAW package 50has found that temperature of the first SAW resonator or device 10(e.g., temperature of at least a portion of the piezoelectric substrate12) increases to approximately 150 degrees Celsius. Such temperatureperformance is undesirable because the first SAW resonator or device 10(e.g., the piezoelectric substrate 12 of the first SAW resonator ordevice 10) can crack or break at temperatures above 100 degrees Celsius.Such temperature performance also prevents the use of the first SAWresonator or device 10 for high power applications (e.g., in a highpower transmit filter). Heat generated by the IDT electrode 24 of thesecond SAW resonator or device 10, shown by arrows H2, is dissipatedfrom the piezoelectric substrate 22 by the vias 28, which transfer saidheat to the electrodes 29 and to a printed circuit board (PCB) on whichthe SAW package or stacked surface acoustic wave device structure 50 ismounted. Therefore, the SAW package or stacked surface acoustic wavedevice structure 50 has power durability limitations due to the hightemperatures the first SAW resonator or device 10 experiences.

FIGS. 3-4 illustrate a packaged acoustic wave component 200 with a first(top or upper) acoustic wave resonator or device or die 210 and a second(bottom or lower) acoustic wave resonator or device or die 240. Thefirst and second acoustic wave resonators or devices or dies 210, 240generate a surface acoustic wave having a wavelength λ or L.

The first acoustic device 210 is supported by a frame 270 on the secondacoustic wave device 240. The first and second acoustic wave resonatorsor devices or dies 210, 240 each have support layer or substrate 216,246, a functional layer 214, 244 disposed over the support layer 216,246, a piezoelectric layer 212, 242 disposed over the functional layer214, 244, and an interdigital transducer (IDT) electrode 218, 248disposed on the piezoelectric layer 212, 242. In some implementations,the functional layer 214, 244 is excluded. The first and second acousticwave resonators or devices or dies 210, 240 therefore have a multi-layerpiezoelectric substrate (MPS) (e.g., are MPS dies). In oneimplementation, only the first acoustic wave device 210 has amulti-layer piezoelectric substrate (MPS) and the second acoustic wavedevice 240 has a piezoelectric layer 242 (e.g., but does not have amulti-layer piezoelectric substrate). Vias 222 extend between metallayers 220, 250 attached to the IDT electrodes 218, 248 of the first andsecond acoustic wave resonators or devices or dies 210, 240. The secondacoustic wave device 240 has vias 254 that extend from the IDT electrode248 to electrodes 256 on an opposite side of the support layer 246 fromthe IDT electrode 248. The second acoustic wave device 240 is spacedapart from and inverted relative to the first acoustic wave device 210so that the second interdigital transducer electrode 248 is spaced apartfrom (e.g., spaced below) and faces the first interdigital transducerelectrode 218.

In one implementation, the first and second acoustic wave devices 210,240 can have the same materials and dimensions. In anotherimplementation, the first and second acoustic wave devices 210, 240 canhave different materials and/or dimensions. In one example, as shown inFIGS. 3-4, the functional layer 214, 244 is coextensive (e.g., extendsacross the same area, extends along the same length) with the supportlayer or substrate 216, 246. In one example, as shown in FIGS. 3-4, thepiezoelectric layer 212, 242 is coextensive (e.g., extends across thesame area, extends along the same length) with the functional layer 214,244. In another implementation, as discussed further below, one or bothof the functional layer 214, 244 and piezoelectric layer 212, 242 is notcoextensive with (e.g., extends across a smaller area than, extendsalong a shorter length than) the support layer or substrate 216, 246.

With respect to the first acoustic wave device 210, the piezoelectriclayer 212 can have a thickness TT1, the functional layer 214 can have athickness TT2 and the support layer or substrate 216 can have athickness TT3. The thickness TT3 of the support layer 216 is greaterthan the thickness TT1, TT2 of the piezoelectric layer 212 and thefunctional layer 214. Optionally, the thickness TT1 of the piezoelectriclayer 212 is substantially equal to the thickness TT2 of the functionallayer 214.

With respect to the second acoustic wave device 240, the piezoelectriclayer 242 can have a thickness TB1, the functional layer 244 can have athickness TB2 and the support layer or substrate 246 can have athickness TB3. The thickness TB3 of the support layer 246 is greaterthan the thickness TB1, TB2 of the piezoelectric layer 242 and thefunctional layer 244. Optionally, the thickness TB1 of the piezoelectriclayer 242 is substantially equal to the thickness TB2 of the functionallayer 244.

In one implementation the thickness TT3, TB3 of the support layers 216,246 are substantially the same. In one implementation the thickness TT2,TB2 of the functional layers 214, 244 are substantially the same. In oneimplementation the thickness TT1, TB1 of the piezoelectric layers 212,242 are substantially the same.

The support layers or substrates 216, 246 of the first and secondacoustic wave resonators or devices or dies 210, 240 are made of amaterial with high thermal conductivity. In one example, the supportlayers 216, 246 are made of silicon. In another example, the supportlayers 216, 246 are made of aluminum nitride (AlN). In another example,the support layers 216, 246 are made of sapphire. In another example,the support layers 216, 246 are made of quartz. The support layers 216,246 have a higher thermal conductivity than the material of thepiezoelectric layers 212, 242.

In one example, the functional layers 214, 244 are temperaturecompensation layers. In another example, the functional layers 214, 244are dielectric layers.

The frame 270 can be made of a thermally conductive material. In oneexample, the frame 270 can be made of a metal, such as copper, tin,gold, etc. Other suitable thermally conductive materials (metal andnon-metal) can also be used for the frame 270. The frame 270, when madeof metal, can be connected to a ground of the packaged acoustic wavecomponent 200.

The frame 270 can in one implementation extend along the periphery ofthe first and second acoustic wave resonators or devices or dies 210,240 to seal or encapsulate the air cavity between the first and secondacoustic wave resonators or devices or dies 210, 240. As shown in FIG.3, the frame 270 extends between (e.g., is in thermal communicationwith, in thermal contact with, in direct contact with) and interconnectsthe first and second acoustic wave devices 210, 240 (e.g., interconnectsthe piezoelectric layers 212, 242 of the first and second acoustic wavedevices 210, 240). The frame 270 supports the first acoustic wave device210 on the second acoustic wave device 240. The frame 270 thermallycommunicates the first acoustic wave device 210 with the second acousticwave device 240. In one example, a width of the frame 270 can beincreased, which can increase the amount of heat the frame 270 transfersfrom the first acoustic wave device 210 to the second acoustic wavedevice 240. Additionally, the vias 222 can thermally communicate thefirst acoustic wave device 210 with the second acoustic wave device 240.

The first acoustic wave device 210 and second acoustic wave device 240can electrically communicate via the vias 222. Said electricalcommunication can be directed to electrodes 256 via the vias 254, andonto a printed circuit board (PCB) on which the packaged acoustic wavecomponent 200 is mounted.

As shown in FIG. 4, heat generated by the IDT electrode 218 of the firstacoustic wave resonator or device or die 210 is directed to the frame270, as shown by arrows C1, to transfer said heat to the second acousticwave resonator or device or die 240. Such heat transfer to the frame 270is facilitated by the high thermal conductivity of the support layer orsubstrate 216 of the first acoustic wave device 210. Additionally,though not shown, heat from the first acoustic wave device 210 can alsobe transferred by the vias 222 to the second acoustic wave device 240.Heat generated by the IDT electrode 248 of the second acoustic wavedevice 240 and heat received from the first acoustic wave device 210(e.g., via the frame 270), shown by arrows C2, is dissipated from thesecond acoustic wave device 240 by the vias 254, which transfer saidheat to the electrodes 256 and to the printed circuit board (PCB) onwhich the packaged acoustic wave component 200 is mounted.

FIGS. 5-6 shows another embodiment of a packaged acoustic wave component200′. Some of the features of the packaged acoustic wave component 200′are similar to features of the package acoustic wave component 200 inFIGS. 3-4. Thus, references numerals used to designate the variouscomponents of the packaged acoustic wave component 200′ are identical tothose used for identifying the corresponding components of the packagedacoustic wave component 200 in FIGS. 3-4. Therefore, the structure anddescription for the various features of the packaged acoustic wavecomponent 200 in FIGS. 3-4 are understood to also apply to thecorresponding features of the packaged acoustic wave component 200′ inFIGS. 5-6, except as described below.

The packaged acoustic wave component 200′ differs from the packagedacoustic wave component 200 in that the functional layer 214′, 244′ andthe piezoelectric layer 212′, 242′ are not coextensive with (e.g.,extends across a smaller area, extends along a shorter length) than thesupport layer 216′, 246′. As shown in FIGS. 5-6, in one example thefunctional layer 214′, 244′ is coextensive with (e.g., extends across asame area as, extends along the same length as) the piezoelectric layer212′, 242′. Additionally, the frame 270′ extends between (e.g., is inthermal communication with, in thermal contact with, in direct contactwith) and interconnects the first and second acoustic wave devices 210′,240′ (e.g., interconnects the support layer or substrate 216′, 246′ ofthe first and second acoustic wave devices 210′, 240′). In one example,a gap G is defined between the frame 270′ and the ends of the functionallayer 214′, 244′ and the piezoelectric layer 212′, 242′ (e.g., toinhibit direct contact between the frame 270 and the functional layer214′, 244′, and the piezoelectric layer 212′, 242′).

With reference to FIG. 6, heat generated by the IDT electrode 218′ ofthe first acoustic wave resonator or device or die 210′ is directed tothe frame 270′, as shown by arrows C1′, to transfer said heat to thesecond acoustic wave resonator or device or die 240′. Such heat transferto the frame 270′ is facilitated by the high thermal conductivity of thesupport layer or substrate 216′ of the first acoustic wave device 210′.Additionally, though not shown, heat from the first acoustic wave device210′ can also be transferred by the vias 222′ to the second acousticwave device 240′. Heat generated by the IDT electrode 248′ of the secondacoustic wave device 240′ and heat received from the first acoustic wavedevice 210′ (e.g., via the frame 270′), shown by arrows C2′, isdissipated from the second acoustic wave device 240′ by the vias 254′,which transfer said heat to the electrodes 256′ and to the printedcircuit board (PCB) on which the packaged acoustic wave component 200′is mounted.

FIGS. 7A-7B show illustrations of thermal testing of the packagedsurface acoustic wave component 200, which show that the temperature ofthe first acoustic wave device 210 of the packaged acoustic wavecomponent 200 does not exceed 40 degrees Celsius during use. In someexamples, the first (top) acoustic wave device 210 of the packagedacoustic wave component 200 achieves an top average temperature ofapproximately 30 degrees Celsius. Accordingly, the packaged acousticwave component 200 advantageously remains under 100 degrees Celsiusduring use, allowing the packaged acoustic wave component 200 to avoidcracks or breaks in the first acoustic wave device 210.

Advantageously, the MPS structure of the packaged acoustic wavecomponent 200, 200′ allows for the reduction in temperature of the firstacoustic wave device 210, 210′ during operation, thereby reducing themechanical stress they first (or top) acoustic wave device 210, 210′ issubjected to and avoid cracks or breaks therein, resulting in improvedmechanical ruggedness of the acoustic wave devices and MPS structure.Such temperature performance advantageously allows use of the firstacoustic wave resonator or device 210, 210′ for high power applications(e.g., in a high power transmit filter), while allowing for a sizereduction in the packaged acoustic wave component 200, 200′.Additionally, the improved thermal performance (e.g., improved heatdissipation) of the packaged acoustic wave component 200, 200′ due tothe improved thermal performance of the first (or top) acoustic wavedevice 210, 210′ allows for a reduction in the die area because filterscan be arranged closer together.

The packaged acoustic wave component 200, 200′ can be formed by formingor providing the second acoustic wave device 240, 240′, forming orproviding and bonding the frame 270, 270′ and vias 222, 222′ to thesecond acoustic wave device 240, 240′, forming or providing the firstacoustic wave device 210, 210′ and boding the first acoustic wave device210, 210′ to the frame 270, 270′ and vias 222, 222′.

The first acoustic wave device 210, 210′ can optionally be formed byforming or providing the support layer or substrate 216, 216′, formingor providing and bonding the functional layer 214, 214′ onto the supportlayer or substrate 216, 216′, forming or providing and bonding thepiezoelectric layer 212, 212′ onto the functional layer 214, 214′, andforming or providing and bonding the IDT electrode 218, 218′ onto thepiezoelectric layer 212, 212′. The second acoustic wave device 240, 240′can optionally be formed by forming or providing the support layer orsubstrate 246, 246′, forming or providing and bonding the functionallayer 244, 244′ onto the support layer or substrate 246, 246′, formingor providing and bonding the piezoelectric layer 242, 242′ onto thefunctional layer 244, 244′, forming the vias 254, 254′ through thepiezoelectric layer 242, 242′, the functional layer 244, 244′, and thesupport layer 246, 246′, forming or providing electrodes 256, 256′ andconnecting them to the vias 254, 254′, and forming or providing andbonding the IDT electrode 248, 248′ onto the piezoelectric layer 242,242′.

The manufacturing process includes bonding the frame 270, 270′ to thefirst acoustic wave device 210, 210′ and second acoustic wave device240, 240′. In one implementation, prior to bonding the frame 270, 270′to the first acoustic wave device 210, 210′ and second acoustic wavedevice 240, 240′, a portion of the piezoelectric layers 212, 212′, 242,242′ and/or a portion of the functional layers 214, 214′, 244, 244′ areremoved so that the frame 270, 270′ can interconnect (e.g., contact)with the support layers 216, 216′, 246, 246′. In one implementation,such portions can be removed after the IDT electrodes 218, 218′, 248,248′ are formed or provided over the piezoelectric layers 212, 212′,242, 242′. In one example, such portions of the piezoelectric layers212, 212′, 242, 242′ and/or the functional layers 214, 214′, 244, 244′can be removed via an etching process.

An MPS acoustic wave resonator or device or die in a packaged acousticwave component, including any suitable combination of features disclosedherein, can be included in a filter arranged to filter a radio frequencysignal in a fifth generation (5G) New Radio (NR) operating band withinFrequency Range 1 (FR1). A filter arranged to filter a radio frequencysignal in a 5G NR operating band can include one or more MPS acousticwave resonators disclosed herein. FR1 can be from 410 MHz to 7.125 GHz,for example, as specified in a current 5G NR specification. In 5Gapplications, the thermal dissipation of the MPS acoustic waveresonators disclosed herein can be advantageous. For example, suchthermal dissipation can be desirable in 5G applications with a highertime-division duplexing (TDD) duty cycle compared to fourth generation(4G) Long Term Evolution (LTE). One or more MPS acoustic wave resonatorsin accordance with any suitable principles and advantages disclosedherein can be included in a filter arranged to filter a radio frequencysignal in a 4G LTE operating band and/or in a filter having a passbandthat includes a 4G LTE operating band and a 5G NR operating band.

FIG. 8A is a schematic diagram of an example transmit filter 100 thatincludes surface acoustic wave resonators according to an embodiment.The transmit filter 100 can be a band pass filter. The illustratedtransmit filter 100 is arranged to filter a radio frequency signalreceived at a transmit port TX and provide a filtered output signal toan antenna port ANT. Some or all of the SAW resonators TS1 to TS7 and/orTP1 to TP5 can be a SAW resonator in accordance with any suitableprinciples and advantages disclosed herein. For instance, one or more ofthe SAW resonators of the transmit filter 100 can be an acoustic wavedevice 210, 210′ of a packaged acoustic wave components 200, 200′ ofFIGS. 3-6. Alternatively or additionally, one or more of the SAWresonators of the transmit filter 100 can be any surface acoustic waveresonator disclosed herein. Any suitable number of series SAW resonatorsand shunt SAW resonators can be included in a transmit filter 100.

FIG. 8B is a schematic diagram of a receive filter 105 that includessurface acoustic wave resonators according to an embodiment. The receivefilter 105 can be a band pass filter. The illustrated receive filter 105is arranged to filter a radio frequency signal received at an antennaport ANT and provide a filtered output signal to a receive port RX. Someor all of the SAW resonators RS1 to RS8 and/or RP1 to RP6 can be SAWresonators in accordance with any suitable principles and advantagesdisclosed herein. For instance, one or more of the SAW resonators of thereceive filter 105 can be an acoustic wave device 210, 210′ of apackaged acoustic wave components 200, 200′ of FIGS. 3-6. Alternativelyor additionally, one or more of the SAW resonators of the receive filter105 can be any surface acoustic wave resonator disclosed herein. Anysuitable number of series SAW resonators and shunt SAW resonators can beincluded in a receive filter 105.

Although FIGS. 8A and 8B illustrate example ladder filter topologies,any suitable filter topology can include a SAW resonator in accordancewith any suitable principles and advantages disclosed herein. Examplefilter topologies include ladder topology, a lattice topology, a hybridladder and lattice topology, a multi-mode SAW filter, a multi-mode SAWfilter combined with one or more other SAW resonators, and the like.

FIG. 9 is a schematic diagram of a radio frequency module 175 thatincludes a surface acoustic wave component 176 according to anembodiment. The illustrated radio frequency module 175 includes the SAWcomponent 176 and other circuitry 177. The SAW component 176 can includeone or more SAW resonators with any suitable combination of features ofthe SAW resonators disclosed herein. The SAW component 176 can include aSAW die that includes SAW resonators.

The SAW component 176 shown in FIG. 9 includes a filter 178 andterminals 179A and 179B. The filter 178 includes SAW resonators. One ormore of the SAW resonators can be implemented in accordance with anysuitable principles and advantages of the acoustic wave devices 210,210′ of the packaged acoustic wave components 200, 200′ of FIGS. 3-6and/or any surface acoustic wave resonator disclosed herein. Theterminals 179A and 178B can serve, for example, as an input contact andan output contact. The SAW component 176 and the other circuitry 177 areon a common packaging substrate 180 in FIG. 9. The package substrate 180can be a laminate substrate. The terminals 179A and 179B can beelectrically connected to contacts 181A and 181B, respectively, on thepackaging substrate 180 by way of electrical connectors 182A and 182B,respectively. The electrical connectors 182A and 182B can be bumps orwire bonds, for example. The other circuitry 177 can include anysuitable additional circuitry. For example, the other circuitry caninclude one or more one or more power amplifiers, one or more radiofrequency switches, one or more additional filters, one or more lownoise amplifiers, the like, or any suitable combination thereof. Theradio frequency module 175 can include one or more packaging structuresto, for example, provide protection and/or facilitate easier handling ofthe radio frequency module 175. Such a packaging structure can includean overmold structure formed over the packaging substrate 180. Theovermold structure can encapsulate some or all of the components of theradio frequency module 175.

FIG. 10 is a schematic diagram of a radio frequency module 184 thatincludes a surface acoustic wave resonator according to an embodiment.As illustrated, the radio frequency module 184 includes duplexers 185Ato 185N that include respective transmit filters 186A1 to 186N1 andrespective receive filters 186A2 to 186N2, a power amplifier 187, aselect switch 188, and an antenna switch 189. In some instances, themodule 184 can include one or more low noise amplifiers configured toreceive a signal from one or more receive filters of the receive filters186A2 to 186N2. The radio frequency module 184 can include a packagethat encloses the illustrated elements. The illustrated elements can bedisposed on a common packaging substrate 180. The packaging substratecan be a laminate substrate, for example.

The duplexers 185A to 185N can each include two acoustic wave filterscoupled to a common node. The two acoustic wave filters can be atransmit filter and a receive filter. As illustrated, the transmitfilter and the receive filter can each be band pass filters arranged tofilter a radio frequency signal. One or more of the transmit filters186A1 to 186N1 can include one or more SAW resonators in accordance withany suitable principles and advantages disclosed herein. Similarly, oneor more of the receive filters 186A2 to 186N2 can include one or moreSAW resonators in accordance with any suitable principles and advantagesdisclosed herein. Although FIG. 10 illustrates duplexers, any suitableprinciples and advantages disclosed herein can be implemented in othermultiplexers (e.g., quadplexers, hexaplexers, octoplexers, etc.) and/orin switch-plexers and/or to standalone filters.

The power amplifier 187 can amplify a radio frequency signal. Theillustrated switch 188 is a multi-throw radio frequency switch. Theswitch 188 can electrically couple an output of the power amplifier 187to a selected transmit filter of the transmit filters 186A1 to 186N1. Insome instances, the switch 188 can electrically connect the output ofthe power amplifier 187 to more than one of the transmit filters 186A1to 186N1. The antenna switch 189 can selectively couple a signal fromone or more of the duplexers 185A to 185N to an antenna port ANT. Theduplexers 185A to 185N can be associated with different frequency bandsand/or different modes of operation (e.g., different power modes,different signaling modes, etc.).

FIG. 11 is a schematic block diagram of a module 190 that includesduplexers 191A to 191N and an antenna switch 192. One or more filters ofthe duplexers 191A to 191N can include any suitable number of surfaceacoustic wave resonators in accordance with any suitable principles andadvantages discussed herein. Any suitable number of duplexers 191A to191N can be implemented. The antenna switch 192 can have a number ofthrows corresponding to the number of duplexers 191A to 191N. Theantenna switch 192 can electrically couple a selected duplexer to anantenna port of the module 190.

FIG. 12A is a schematic block diagram of a module 410 that includes apower amplifier 412, a radio frequency switch 414, and duplexers 191A to191N in accordance with one or more embodiments. The power amplifier 412can amplify a radio frequency signal. The radio frequency switch 414 canbe a multi-throw radio frequency switch. The radio frequency switch 414can electrically couple an output of the power amplifier 412 to aselected transmit filter of the duplexers 191A to 191N. One or morefilters of the duplexers 191A to 191N can include any suitable number ofsurface acoustic wave resonators in accordance with any suitableprinciples and advantages discussed herein. Any suitable number ofduplexers 191A to 191N can be implemented.

FIG. 12B is a schematic block diagram of a module 415 that includesfilters 416A to 416N, a radio frequency switch 417, and a low noiseamplifier 418 according to an embodiment. One or more filters of thefilters 416A to 416N can include any suitable number of acoustic waveresonators in accordance with any suitable principles and advantagesdisclosed herein. Any suitable number of filters 416A to 416N can beimplemented. The illustrated filters 416A to 416N are receive filters.In some embodiments (not illustrated), one or more of the filters 416Ato 416N can be included in a multiplexer that also includes a transmitfilter. The radio frequency switch 417 can be a multi-throw radiofrequency switch. The radio frequency switch 417 can electrically couplean output of a selected filter of filters 416A to 416N to the low noiseamplifier 418. In some embodiments (not illustrated), a plurality of lownoise amplifiers can be implemented. The module 415 can includediversity receive features in certain applications.

FIG. 13A is a schematic diagram of a wireless communication device 420that includes filters 423 in a radio frequency front end 422 accordingto an embodiment. The filters 423 can include one or more SAW resonatorsin accordance with any suitable principles and advantages discussedherein. The wireless communication device 420 can be any suitablewireless communication device. For instance, a wireless communicationdevice 420 can be a mobile phone, such as a smart phone. As illustrated,the wireless communication device 420 includes an antenna 421, an RFfront end 422, a transceiver 424, a processor 425, a memory 426, and auser interface 427. The antenna 421 can transmit/receive RF signalsprovided by the RF front end 422. Such RF signals can include carrieraggregation signals. Although not illustrated, the wirelesscommunication device 420 can include a microphone and a speaker incertain applications.

The RF front end 422 can include one or more power amplifiers, one ormore low noise amplifiers, one or more RF switches, one or more receivefilters, one or more transmit filters, one or more duplex filters, oneor more multiplexers, one or more frequency multiplexing circuits, thelike, or any suitable combination thereof. The RF front end 422 cantransmit and receive RF signals associated with any suitablecommunication standards. The filters 423 can include SAW resonators of aSAW component that includes any suitable combination of featuresdiscussed with reference to any embodiments discussed above.

The transceiver 424 can provide RF signals to the RF front end 422 foramplification and/or other processing. The transceiver 424 can alsoprocess an RF signal provided by a low noise amplifier of the RF frontend 422. The transceiver 424 is in communication with the processor 425.The processor 425 can be a baseband processor. The processor 425 canprovide any suitable base band processing functions for the wirelesscommunication device 420. The memory 426 can be accessed by theprocessor 425. The memory 426 can store any suitable data for thewireless communication device 420. The user interface 427 can be anysuitable user interface, such as a display with touch screencapabilities.

FIG. 13B is a schematic diagram of a wireless communication device 430that includes filters 423 in a radio frequency front end 422 and asecond filter 433 in a diversity receive module 432. The wirelesscommunication device 430 is like the wireless communication device 400of FIG. 13A, except that the wireless communication device 430 alsoincludes diversity receive features. As illustrated in FIG. 13B, thewireless communication device 430 includes a diversity antenna 431, adiversity module 432 configured to process signals received by thediversity antenna 431 and including filters 433, and a transceiver 434in communication with both the radio frequency front end 422 and thediversity receive module 432. The filters 433 can include one or moreSAW resonators that include any suitable combination of featuresdiscussed with reference to any embodiments discussed above.

Although embodiments disclosed herein relate to surface acoustic waveresonators, any suitable principles and advantages disclosed herein canbe applied to other types of acoustic wave resonators that include anIDT electrode, such as Lamb wave resonators and/or boundary waveresonators. For example, any suitable combination of features of thetilted and rotated IDT electrodes disclosed herein can be applied to aLamb wave resonator and/or a boundary wave resonator.

Any of the embodiments described above can be implemented in associationwith mobile devices such as cellular handsets. The principles andadvantages of the embodiments can be used for any systems or apparatus,such as any uplink wireless communication device, that could benefitfrom any of the embodiments described herein. The teachings herein areapplicable to a variety of systems. Although this disclosure includessome example embodiments, the teachings described herein can be appliedto a variety of structures. Any of the principles and advantagesdiscussed herein can be implemented in association with RF circuitsconfigured to process signals in a frequency range from about 30 kHz to300 GHz, such as in a frequency range from about 450 MHz to 8.5 GHz.Acoustic wave resonators and/or filters disclosed herein can filter RFsignals at frequencies up to and including millimeter wave frequencies.

Aspects of this disclosure can be implemented in various electronicdevices. Examples of the electronic devices can include, but are notlimited to, consumer electronic products, parts of the consumerelectronic products such as packaged radio frequency modules and/orpackaged filter components, uplink wireless communication devices,wireless communication infrastructure, electronic test equipment, etc.Examples of the electronic devices can include, but are not limited to,a mobile phone such as a smart phone, a wearable computing device suchas a smart watch or an ear piece, a telephone, a television, a computermonitor, a computer, a modem, a hand-held computer, a laptop computer, atablet computer, a microwave, a refrigerator, a vehicular electronicssystem such as an automotive electronics system, a stereo system, adigital music player, a radio, a camera such as a digital camera, aportable memory chip, a washer, a dryer, a washer/dryer, a copier, afacsimile machine, a scanner, a multi-functional peripheral device, awrist watch, a clock, etc. Further, the electronic devices can includeunfinished products.

Unless the context clearly requires otherwise, throughout thedescription and the claims, the words “comprise,” “comprising,”“include,” “including” and the like are to be construed in an inclusivesense, as opposed to an exclusive or exhaustive sense; that is to say,in the sense of “including, but not limited to.” The word “coupled”, asgenerally used herein, refers to two or more elements that may be eitherdirectly connected, or connected by way of one or more intermediateelements. Likewise, the word “connected”, as generally used herein,refers to two or more elements that may be either directly connected, orconnected by way of one or more intermediate elements. As used herein,the term “approximately” intends that the modified characteristic neednot be absolute, but is close enough so as to achieve the advantages ofthe characteristic. Additionally, the words “herein,” “above,” “below,”and words of similar import, when used in this application, shall referto this application as a whole and not to any particular portions ofthis application. Where the context permits, words in the above DetailedDescription using the singular or plural number may also include theplural or singular number respectively. The word “or” in reference to alist of two or more items, that word covers all of the followinginterpretations of the word: any of the items in the list, all of theitems in the list, and any combination of the items in the list.

Moreover, conditional language used herein, such as, among others,“can,” “could,” “might,” “may,” “e.g.,” “for example,” “such as” and thelike, unless specifically stated otherwise, or otherwise understoodwithin the context as used, is generally intended to convey that certainembodiments include, while other embodiments do not include, certainfeatures, elements and/or states. Thus, such conditional language is notgenerally intended to imply that features, elements and/or states are inany way required for one or more embodiments or that one or moreembodiments necessarily include logic for deciding, with or withoutauthor input or prompting, whether these features, elements and/orstates are included or are to be performed in any particular embodiment.

While certain embodiments have been described, these embodiments havebeen presented by way of example only, and are not intended to limit thescope of the disclosure. Indeed, the novel apparatus, methods, andsystems described herein may be embodied in a variety of other forms;furthermore, various omissions, substitutions and changes in the form ofthe methods and systems described herein may be made without departingfrom the spirit of the disclosure. For example, while blocks arepresented in a given arrangement, alternative embodiments may performsimilar functionalities with different components and/or circuittopologies, and some blocks may be deleted, moved, added, subdivided,combined, and/or modified. Each of these blocks may be implemented in avariety of different ways. Any suitable combination of the elements andacts of the various embodiments described above can be combined toprovide further embodiments. The accompanying claims and theirequivalents are intended to cover such forms or modifications as wouldfall within the scope and spirit of the disclosure.

What is claimed is:
 1. A packaged acoustic wave component comprising: afirst acoustic wave device including a first multi-layer piezoelectricsubstrate and a first interdigital transducer electrode, the firstmulti-layer piezoelectric substrate including a first piezoelectriclayer and support layer, the support layer having a higher thermalconductivity than the first piezoelectric layer; a second acoustic wavedevice including a second piezoelectric layer and second interdigitaltransducer electrode, the first acoustic wave device stacked with thesecond acoustic wave device so that the first and second interdigitaltransducer electrodes face and are spaced apart from each other; and athermally conductive frame interposed between the first and secondacoustic wave devices, the first multi-layer piezoelectric substratebeing configured to direct heat generated by the first acoustic wavedevice to the second acoustic wave device by way of the thermallyconductive frame to dissipate heat from the first acoustic wave device.2. The packaged acoustic wave component of claim 1 further comprising afirst functional layer interposed between the first support layer andthe first piezoelectric layer.
 3. The packaged acoustic wave componentof claim 1 wherein the second acoustic wave device includes a secondmulti-layer piezoelectric substrate including the second piezoelectriclayer disposed over a second support layer.
 4. The packaged acousticwave component of claim 3 further comprising a second functional layerinterposed between the second support layer and the second piezoelectriclayer.
 5. The packaged acoustic wave component of claim 1 wherein thefirst support layer is made of a material chosen from a group consistingof silicon, aluminum nitride, sapphire and quartz.
 6. The packagedacoustic wave component of claim 1 wherein the first support layer has alarger thickness than the first piezoelectric layer.
 7. The packagedacoustic wave component of claim 1 wherein a temperature of the firstacoustic wave device increases to no more than approximately 30 degreesCelsius during operation of the second acoustic wave device.
 8. A radiofrequency module comprising: a package substrate; a packaged acousticwave component including a first acoustic wave device including a firstmulti-layer piezoelectric substrate including a first piezoelectriclayer disposed over a first support layer and a first interdigitaltransducer electrode, a second acoustic wave device including a secondpiezoelectric layer and second interdigital transducer electrode, thefirst acoustic wave device stacked with the second acoustic wave deviceso that the first and second interdigital transducer electrodes face andare spaced apart from each other, and a thermally conductive frameinterposed between the first and second acoustic wave devices, the firstmulti-layer piezoelectric substrate being configured to direct heatgenerated by the first acoustic wave device to the second acoustic wavedevice by way of the thermally conductive frame to dissipate heat fromthe first acoustic wave device; and additional circuitry, the packagedacoustic wave component and additional circuitry disposed on the packagesubstrate.
 9. The radio frequency module of claim 8 wherein thethermally conductive frame contacts the first support layer.
 10. Theradio frequency module of claim 8 further comprising a first functionallayer interposed between the first support layer and the firstpiezoelectric layer.
 11. The radio frequency module of claim 8 whereinthe second acoustic wave device includes a second multi-layerpiezoelectric substrate including the second piezoelectric layerdisposed over a second support layer.
 12. The radio frequency module ofclaim 11 further comprising a second functional layer interposed betweenthe second support layer and the second piezoelectric layer.
 13. Theradio frequency module of claim 8 wherein the first support layer ismade of a material chosen from a group consisting of silicon, aluminumnitride, sapphire and quartz.
 14. The radio frequency module of claim 8wherein the first support layer has a larger thickness than the firstpiezoelectric layer.
 15. The radio frequency module of claim 8 wherein atemperature of the first acoustic wave device increases to no more thanapproximately 30 degrees Celsius during operation of the second acousticwave device.
 16. A wireless communication device comprising: an antenna;and a front end module including one or more packaged acoustic wavecomponents configured to filter a radio frequency signal associated withthe antenna, each surface packaged acoustic wave component including afirst acoustic wave device including a first multi-layer piezoelectricsubstrate including a first piezoelectric layer disposed over a firstsupport layer and a first interdigital transducer electrode, a secondacoustic wave device including a second piezoelectric layer and secondinterdigital transducer electrode, the first acoustic wave devicestacked with the second acoustic wave device so that the first andsecond interdigital transducer electrodes face and are spaced apart fromeach other, and a thermally conductive frame interposed between thefirst and second acoustic wave devices, the first multi-layerpiezoelectric substrate being configured to direct heat generated by thefirst acoustic wave device to the second acoustic wave device by way ofthe thermally conductive frame to dissipate heat from the first acousticwave device.
 17. The radio frequency module of claim 16 wherein thethermally conductive frame contacts the first support layer.
 18. Thewireless communication device of claim 16 further comprising a firstfunctional layer interposed between the first support layer and thefirst piezoelectric layer.
 19. The wireless communication device ofclaim 16 wherein the second acoustic wave device includes a secondmulti-layer piezoelectric substrate including the second piezoelectriclayer disposed over a second support layer.
 20. The wirelesscommunication device of claim 19 further comprising a second functionallayer interposed between the second support layer and the secondpiezoelectric layer.
 21. The wireless communication device of claim 16wherein the first support layer is made of a material chosen from agroup consisting of silicon, aluminum nitride, sapphire and quartz. 22.The wireless communication device of claim 16 wherein the first supportlayer has a larger thickness than the first piezoelectric layer.
 23. Thewireless communication device of claim 16 wherein a temperature of thefirst acoustic wave device increases to no more than approximately 30degrees Celsius during operation of the second acoustic wave device.